Affordable Access

Publisher Website

Influenza epidemics observed in primary care from 1984 to 2017 in France: a decrease of epidemic size over time.

  • Souty, Cécile1
  • Amoros, Philippe1
  • Falchi, Alessandra2
  • Capai, Lisandru1, 2
  • Bonmarin, Isabelle3
  • van der Werf, Sylvie4, 5, 6, 7
  • Masse, Shirley1, 2
  • Turbelin, Clément1
  • Rossignol, Louise1
  • Vilcu, Ana-Maria1
  • Lévy-Bruhl, Daniel3
  • Lina, Bruno8, 9
  • Minodier, Laëtitia2
  • Dorléans, Yves1
  • Guerrisi, Caroline1
  • Hanslik, Thomas1, 10, 11
  • Blanchon, Thierry1
  • 1 Sorbonne Universités, INSERM, Institut Pierre Louis d'Épidémiologie et de Santé Publique (IPLESP), F-75012, Paris, France. , (France)
  • 2 EA7310, Laboratoire de Virologie, Université de Corse-Inserm, FR- 20250, Corte, France. , (France)
  • 3 Department of Infectious Diseases, Santé Publique France, F-954415, Saint-Maurice, France. , (France)
  • 4 Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France. , (France)
  • 5 Institut Pasteur, Centre Coordonnateur du Centre National de Référence des virus des infections respiratoires (dont la grippe), Paris, France. , (France)
  • 6 UMR CNRS 3569, 75015, Paris, France. , (France)
  • 7 Université Paris Diderot, Sorbonne Paris Cité, Unité de Génétique Moléculaire des Virus à ARN, Paris, France. , (France)
  • 8 Hospices Civils de Lyon, Laboratoire de Virologie, Institut des Agents Infectieux (IAI), Centre National de Référence des virus respiratoires (dont la grippe), Centre de Biologie et de Pathologie Nord, Groupement Hospitalier Nord, Lyon, France. , (France)
  • 9 Université de Lyon, Virpath, CIRI, INSERM U1111, CNRS UMR5308, ENS Lyon, Université Claude Bernard Lyon 1France. , (France)
  • 10 Université de Versailles Saint-Quentin-en-Yvelines, UVSQ, UFR de Médecine, FR-78000, Versailles, France. , (France)
  • 11 Service de Médecine Interne, Hôpital Ambroise Paré, Assistance Publique - Hôpitaux de Paris, APHP, FR-92100, Boulogne Billancourt, France. , (France)
Published Article
Influenza and Other Respiratory Viruses
Wiley (Blackwell Publishing)
Publication Date
Nov 14, 2018
DOI: 10.1111/irv.12620
PMID: 30428158


Epidemiological analysis of past influenza epidemics remains essential to understand the evolution of the disease and optimize control and prevention strategies. Here, we aimed to use data collected by a primary care surveillance system over the last three decades to study trends in influenza epidemics and describe epidemic profiles according to circulating influenza viruses. Influenza-like illness (ILI) weekly incidences were estimated using cases reported by general practitioners participating in the French Sentinelles network, between 1984 and 2017. Influenza epidemics were detected by applying a periodic regression to this time series. Epidemic (co-)dominant influenza virus (sub)types were determined using French virology data. During the study period, 297607 ILI cases were reported allowing the detection of 33 influenza epidemics. On average, seasonal epidemics lasted 9 weeks and affected 4.1% of the population (95%CI [3.5;4.7]). Mean age of cases was 29 years. Epidemic size decreased over time by -66 cases per 100000 population per season on average (95%CI [-132;-0.2], pval=0.049) and epidemic height decreased by -15 cases per 100000 (95%CI [-28;-2], pval=0.022). Epidemic duration appeared stable over time. Epidemics were mostly dominated by A(H3N2) (n=17, 52%), associated to larger epidemic size, higher epidemic peak and older age of cases. The declining trend in influenza epidemic size and height over the last 33 years might be related to several factors like increased vaccine coverage, hygiene improvements or changing in influenza viruses. However, further researches are needed to assess the impact of potential contributing factors to adapt influenza plans. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Report this publication


Seen <100 times